All
of a sudden my old ranch truck started burning oil.It is a '88 Chevy ¾ ton pickup with a 350 V8 engine,
a manual transmission, and it has about 190,000 miles on it.I know that there are a
few leaks, as it will
mark its spot if I park it over a clean part of my driveway; however, the spots are only three or
four inches
across.It also
blows some blue smoke
out of the exhaust when I start it and when I shift gears, but not when
I am
running at a steady speed.I
checked a
couple of spark plugs and they were dark colored, but not oil-fouled.The problem is that after
three or four days of use,
it usually needs one and sometimes two quarts of oil.Six months ago, I could go three or four weeks
before
it would need a quart of oil.

Would
a new set of rings cure the oil use?

Getting
in the Oil Business

Dear
Oil Business;

From
your letter, I don't think that a set of new piston rings will help all
that
much.Rings usually
do not cause an
increase in oil loss ‘all of a sudden,’ unless the engine has some
other
problem-- like overheating.Also,
installing new piston rings is not as easy as it use to be.To begin with, all of the
fuel-injection and
related sensors are a real headache to remove and get hooked back up
correctly.With
190,000 miles, there will
be a ring-ridge at the very top of the cylinders that must be removed
so that
the pistons will not have broken ring-lands when they are removed.Speaking of removing the
pistons, there is
not enough room under the engine to get the oil pan off.The frame cross-member is
in the way.If you
can not get the oil pan off, then you
can not unbolt the piston’s connecting-rods from the crankshaft to get
the
pistons out.Really,
you should pull the
engine out of the truck.Do
you
really want to put in new rings in the engine without putting in new
connecting-rod bearings?You
would be restoring the
pistons ability to produce power and then putting that power through
old rod
bearings.Even if
you put new rings and
bearings, that would not address the oil that is lost through the worn
valve-guides in the cylinder head.By the way,
that is probably where the oil is coming from that produces the blue
smoke on
start-up and when shifting gears.To
address all of the worn components that could possibly be causing the
oil loss
is going to run you anywhere from about $1,500 to $2,000.Are you aware that you can
get a rebuilt
engine from most of the auto parts houses for about $1,800?It would come with a one
year warranty, too.

Something tells
me that the ‘sudden’ oil loss may not be related to the
engine’s internal condition.What
I
would suggest is to park the truck over a clean area in the driveway
and let
the engine run for 10 or 15 minutes.If
there were one or two quarts of oil going through the engine, there
would most likely be oil-fouled spark-plugs, so I bet that a recent bad
oil leak is causing the loss of oil. I
suspect
that one or more of the spots will be much bigger than three or four
inches in
diameter.Then you
can follow the trail
of oil up to the real bad leak that is at its worst only when the
engine is
running.

Happy
hunting

Herr
Professor Nuzanbolts

Followup:

Not
in the Oil Business took my advice.He
found that the oil-pressure sensor was leaking rather badly.The repair cost him $5.88
for a new oil
pressure sensor--which he installed himself.